Slit lamp apparatus with peripheral illumination

ABSTRACT

A split lamp apparatus includes a peripheral lighting arrangement (3) which can rotate about a vertical axis (5, 6) independently of other parts (1, 2) of the apparatus. In this way, the spot of light from the auxiliary lighting is always located in the focal plane of the slit lamp device (2) and of a stereomicroscope (1). The peripheral lighting arrangement can also be replaced by a laser light source.

FIELD OF THE INVENTION

The invention relates to a slit lamp apparatus comprising astereomicroscope, a slit illuminating about a vertical axis, aperipheral illuminating device and an apparatus mechanism coupling thestereomicroscope and the illuminating devices.

BACKGROUND OF THE INVENTION

Slit lamp apparatus which have a peripheral illuminating device inaddition to the slit illuminating device are known as so-calledphoto-slit lamps and are described in the paper "Augenuntersuchung mitder Spaltlampe" published by Carl Zeiss, Oberkochen. With these knownphoto-slit lamps, it is disadvantageous that the incidence angle of theperipheral illuminating device can only be changed when thisilluminating device is pivoted together with the stereomicroscope aboutthe rotational axis of the apparatus mechanism about which the slitilluminating device is also pivotable.

The plane of the slit image and the microscope focal plane contain thevirtual extension line of this rotational axis. By means of aninstrument base, this plane can be displaced in X, Y, Z direction at thelocation of the examination in the eye. The mechanical support of thiscommon rotational axis for the slit illuminating device and for thestereomicroscope can be arranged above or below the head of the patientin accordance with the configuration of the slit lamp device.

SUMMARY OF THE INVENTION

The present invention has as an object to equip known slit lamp deviceswith an additional illuminating device having a direction of incomingradiation which is independent of other apparatus parts and which can bechanged independently of the slit illuminating device.

The split lamp apparatus of the invention includes a stereomicroscope, aslit lamp device rotatable about a vertical axis, a peripheralilluminating device and an apparatus mechanism. The apparatus mechanismcouples the stereomicroscope and the slit lamp device and a peripheralilluminating device which is also part of the slit lamp apparatus.According to a feature of the invention, the peripheral illuminatingdevice is rotatable about a vertical axis independently of other partsof the slit lamp apparatus.

The advantages achieved with the invention are that the axes of the slitilluminating device and of the peripheral illuminating device can bearranged isocentrically to each other whereby it is assured that theilluminating spot of the additional illumination is always located inthe focal plane of the slit illuminating device and of thestereomicroscope. A further advantage of the invention is that in lieuof the peripheral illumination, a laser light source can be arranged.With a laser slit lamp of this kind, it is possible to select thedirection of incoming radiation of the laser independently of theviewing direction of the microscope and of the direction of incomingradiation of the slit illumination.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are illustrated in the drawing and are morecarefully described in the following The drawing shows:

FIG. 1 a perspective illustration of a slit lamp apparatus having anadditional peripheral illumination rotatable about a vertical axis;

FIG. 2 a section view of the slit lamp device shown in FIG. 1;

FIG. 3 a section view of a laser slit lamp;

FIG. 4 a section view of a slit lamp apparatus wherein the peripheralillumination is arranged above the eye of the patient.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

In the illustration of FIG. 1, a stereomicroscope is identified withreference numeral 1, a slit illuminating device with 2, a peripheralilluminating device with 3 and the apparatus mechanism with 4. The chinsupport is identified with 4a, the device 4b for holding the headsupport 4c for the patient. The illuminating device 3 is rotatable aboutthe axis 6 which extends isocentrically to the rotational axis 5. Theilluminating device 3 is closed by a window 7 for passing theilluminating radiation.

As shown in FIG. 1, the apparatus 4 includes a frame 24 having a firstleg 26, a second leg 28 and a connecting piece 30 interconnecting thelegs. The slit illuminating device 2 is rotatably mounted on the firstleg 26 at a first position thereon so as to define a vertical first axis5 of rotation. The stereomicroscope 1 is mounted on the connecting piece30 of the frame 24. A peripheral illuminating device 3 is rotatablymounted on the second leg 28 of the frame 24 at a second positionthereon so as to be rotatable about a vertical second axis 6independently of the stereomicroscope 1 and the slit illuminating device2. The first vertical axis 5 is coaxial with the second vertical axis 6as shown.

The optical elements for the slit lamp device are shown in the sectionview of FIG. 2. These elements are not identified individually becausethey are evident from the known state of the art. The patient eye isidentified in this illustration with the reference numeral 8 and theviewing eye with 9. The reference numeral 10 identifies a photographicdevice for documentation to which the viewing beam can be directed viathe hinged mirror 11 when required. In addition, the same referencenumerals are used for like apparatus parts as in FIG. 1. Theillustration of FIG. 3 shows the same arrangement as FIG. 2 except forthe laser light source 12. In this apparatus, the radiation of the lightsource 12 can be directed to the patient eye 8 for therapeuticalpurposes in lieu of the peripheral illumination.

A slit lamp apparatus having apparatus mechanism 14 is shown in theillustration of FIG. 4 wherein the slit illuminating device 22 ismounted below the patient eye 8 and the peripheral illuminating device 3is arranged above the patient eye 8. The rotational axis 16 of theperipheral illuminating device extends isocentrically to the rotationalaxis of the slit lamp illuminating device.

We claim:
 1. A slit lamp apparatus comprising:a frame; a slitilluminating device rotatably mounted on said frame at a first positionthereon so as to define a vertical first axis of rotation at said firstposition; a stereomicroscope mounted on said frame; a peripheralilluminating device pivotally mounted on said frame at a second positionthereon so as to be pivotable about a vertical second axis at saidsecond position independently of said stereomicroscope and said slitilluminating device, said first and second axes being isocentric.
 2. Theslit lamp apparatus of claim 1, said stereomicroscope and said slitilluminating device each defining a focal plane; and, said peripheralilluminating device generating an illuminating spot and being mounted atsaid second position so as to cause said second axis to be isocentric tosaid first axis whereby said illuminating spot is always located in thefocal plane of said slit illuminating device and the focal plane of saidstereomicroscope.
 3. The slit lamp apparatus of claim 2, said framehaving a head support thereon for bracing the head of a patient duringan examination; and, said peripheral illuminating device being mountedon said frame so as to cause said peripheral illuminating device to beat an elevation higher than said head support.
 4. The slit lampapparatus of claim 2, said frame having a head support thereon forbracing the head of a patient during an examination; and, saidperipheral illuminating device being mounted on said frame so as tocause said peripheral illuminating device to be at an elevation lowerthan said head support.
 5. A slit lamp apparatus comprising:a framebeing side mounted and having first and second legs and a connectingpiece interconnecting said legs; a slit illuminating device rotatablymounted on said first leg at a first position thereon so as to define avertical first axis of rotation; a stereomicroscope mounted on saidconnecting piece of said frame; a peripheral illuminating devicerotatably mounted on said second leg of said frame at a second positionthereon so as to be rotatable about a vertical second axis independentlyof said stereomicroscope and said slit illuminating device; and, saidsecond axis being coaxial with said first axis.